What with their ukuleles and their homespun ballads about the sci-fi series "Dr. Who," and their addictive EPs and ability to get famous authors to pay attention to their ukulele music about minor plot twists on "Dr. Who." I mean, am I right or am I right? Or maybe that's just Allegra Rosenberg?

In all the usual ways, she seems familiar: She's 16, full of beans, lives in Skokie in a middle-class block. The doorbell on her house is shaped like a frog. She has a thoughtful mom and dad who regard her with a mix of exhausted wariness and pride. She has braces, dark, raccoony eyes and giant red hair that doesn't cascade so much as tsunami. Meeting her, you are not shocked to learn that Allegra, a sophomore at Niles North High School, takes honors classes. Or that she's in art club, design club, school plays. She comes off alarmingly precious. She's culturally omniscient, online more than she is offline. She is a 21st century teenager.

And yet, let me just say it: I have seen the future of Trock Rock, and its name is Allegra Rosenberg.

Trock Rock is short for "Time Lord Rock," a sub-sub-subgenre of pop that celebrates "Dr. Who." Chameleon Circuit? The Radiohead of Trock Rock. Allegra is more of an indie upstart, "though (she's) one of the people who always comes up when you talk about Trock," says Perry Michael Simon, who edits "The Nerdist," comedian Chris Hardwick's popular, geek-centric website. "She has a kind of Billy Bragg vibe — no accompaniment, just her and a ukulele. She's a great example of unfiltered creativity kids put out because they have these digital tools. Though if I were that age, I'm not sure I'd have picked up a ukulele and played songs about 'Dr. Who.'"

Not a "Dr. Who" devotee? Then you missed the big "Dr. Who" convention in Lombard on Thanksgiving weekend, where Allegra was the young, busking redhead, surrounded by admirers listening to lyrics like: "Demons run when a good man goes to war/ The eye-patch lady's taken the baby/ But we don't know what for."

Allegra has written 30 Trock Rock numbers, the finest of which are collected on "Say Hello," her recent, bedroom-recorded EP — "songs that have been literally stuck in my head all week," says Matt Stein, vice president of promotions and creative services for BBC America, which shows the British "Dr. Who" in the United States. Allegra has a blog and YouTube channel devoted to her music ("Stop! It's Ginger Time!") with more than 2,400 subscribers — a minuscule number compared with a Chameleon Circuit-level Trock Rock act, she points out. But the songs themselves are charming and clever enough that the BBC asked her to write a tune for its commercial promoting the esteemed network's Christmas Trock Rock song contest (a song later covered in BBC promos by Dresden Dolls singer Amanda Palmer and comedian Reggie Watts).

Says Kenyatta Cheese, a well-regarded tech guru who develops content for the BBC (and created the phenomena-tracking website "Know Your Meme"): "We're big fans of Allegra's music. There's this whole generation of fans who know how to use GarageBand and Photoshop the way that my generation knew how to work a Nintendo controller. They're creating fan art and music and memes based on what's happening in (an episode). What may seem like a really small moment on-screen can turn into an entire world online."

Her biggest fan, though?

The popular fantasy author Neil Gaiman, who gave her a boost last summer when he came across a song that she wrote inspired by an episode of "Dr. Who" that he wrote. Gaiman tweeted: "Took me 3 years of scribbling & rewrites to make 45 minutes of Dr. Who, summed up in 2:29 by a smart girl with a ukulele."

Big, humongous love

Allegra (pronounced the same way as the popular allergy drug) doesn't speak, exactly — words tumble from her in the hyper-confident gush you thought only existed on "Gossip Girl," though each sentence bangs into the back of the sentence in front of it, like schoolchildren standing in line. She speaks quickly, excitedly, and offhandedly swipes at her face as flecks of spit fly.

"This is what I love," she says, bouncing on her bed, waving a hand across a patchwork of posters on her bedroom wall: "I love 'Dr. Who.' I love 'Supernatural.' I love StarKid. I love 'Harry Potter.' I loved the third 'Harry Potter' movie the best. I know nobody likes the third the best because it doesn't mesh well and takes liberties, but I like it best and it's different. I love 'Homestuck' — you would think an online comic about 13-year-olds wouldn't be retro-romance, right? You'd be wrong. I love Postal Service. I love Ellie Goulding. I love Darren Criss. I love Death Cab for Cutie. I used to love 'Fringe,' but not so much now. I love end-of-the-world scenarios and I find love-in-the-time-of-great-danger scenarios particularly appealing. I also love the Chameleon Circuit, which do what I do, but they are so much more popular and don't really do it how I do it."

If you're not 16: Goulding is a singer, Criss is an actor-singer, Postal Service is a band (featuring Ben Gibbard, also in Death Cab for Cutie) and StarKid is a theater company (whose membership includes Criss). The titles on Allegra's bookshelves, though, run surprisingly deep, stuffed with everything from popular fantasy fiction to Philip K. Dick and Jeffrey Eugenides; if you were to run into Allegra, she would remind you of an articulate version of the happy kids that Gilda Radner and Amy Poehler played on "Saturday Night Live."

But Allegra has a dark secret.

"A very dark secret," she intones. "An incredibly dark secret." She nods at a picture behind me, a framed photo of a young Allegra with another girl, standing back to back. That's her best friend Talia Wertico. They are 9 in the picture, which appeared on the cover of their first (and only) album, "Songs for the Swing Set." It was self-published and recorded with the help of her father, a working musician and music producer.

"It was so inane," she says. "We wrote the songs at summer camp. Songs about leaves and things, seeing puppies in the window. Eight years later, I had to record something that would up the shame of that CD!"

When I ask about influences, she immediately goes into a long admiration of Tavi Gevinson, the 15-year-old Oak Park native who has parlayed a quirky, original fashion blog, rookiemag.com, into a little juice in the fashion world: "She has taken this Internet empowerment thing and ridden it the whole way! And this is just the start! She is the kind of person who would probably be a part of the fashion world anyway, but she's made a place for herself now." When I ask about Gaiman, and mention that I heard he was recording an NPR show in Chicago the next day, she lit up and quickly tweeted him and asked for tickets. He replied fast — does she want tickets? Then I ask if she would ask him for a comment for this story. She does, and we keep a long vigil.

There's a tap at her door.

Her mom, Rachel Rosenberg, executive director of the Ravenswood-based Safer Pest Control Project, slides open the bedroom door and steps in. "How are you guys doing?" she says. "I am Allegra's PR person."

Allegra rolls her eyes.

"I don't know where this'll take her," Rachel says. "But I support it. Even when she was younger, her lyrics — and I thought it would be a joke — were very literate, interesting. But I don't really pay much attention."

"Allegra, I am going to talk, OK? You overtalk, OK?" Rachel turns to me. "See, kids have these online lives that adults don't really understand yet, I think. It's how they hang out with friends. I would make plans to meet with friends when I was a kid. These kids don't feel compelled because they have online communities. If you were a geek when I was young, you just suffered. These kids are virtually with friends all the time."

"It's not a geek thing, mom."

"Oh, Allegra. You online is a different way of being. Not a different way of being young. Of being."

"I'm reading the biography," Rachel says, turning to her daughter, "and he could be a jerk."

Allegra sighs.

"Kids these days," her mother says, then catches herself and adds, "Such a cliche."

'A series of obsessions'

Allegra doesn't know what she wants to be when she grows up.

She seems to be the only one. Vanessa Hojda, 20, a college student from Toronto who became friends with Allegra after writing a fan letter, said: "Allegra has this intrinsic creative thing. I see her getting bigger, going down a creative path, but I don't think it's going to be tied to 'Dr. Who.'" Said Talia, her best friend: "Allegra and I have been friends since we were born, and everyone has always predicted that she'd be famous."

Her parents aren't pressuring her; understandably, they don't know what to do with a 16-year-old who has achieved a modicum of ukulele-based success. Downstairs, on the family couch, Stuart Rosenberg, her dad, one of the investors behind the small Evanston performance space named SPACE, a big guy with a gentle, old-hippy vibe, tells me a story: Because he's a musician and plays in bands and produces music, he started her early on piano lessons. She played for seven years. It never took. "I remember one time quietly suggesting how to play something. She started crying. She wanted to do it her way. And to suggest how things might be done ... she doesn't like the pressure." So when she came back from summer camp a year ago and asked to play ukulele — because a friend had a ukulele, "because the ukulele is the coolest thing ever, perfect for standing, perfect for sitting," she says — he bought a ukulele.

After Gaiman tweeted his endorsement of her talents, her YouTube channel became popular and she decided to record her EP. Her dad would walk by her room, leave recording cables he thought she could use, suggest that maybe they go to Evanston, use the recording studio attached to SPACE. She didn't see the point — she had a good microphone, a computer, a quiet bedroom to record in. What else does a kid need?

"I'm endlessly fascinated by all this," Stuart says, sounding very much like a 20th century parent with a 21st century kid. "The way she has created not only the work but the context for it, the space for the work to be appreciated in. There's no intermediation, no publishing firm, no record company. When she was younger, her songs about leaves and things like that — it was pure sensation. And she's only refined her skills."

Rachel, sitting on the arm of the couch, nods, then says: "She is writing songs about 'Dr. Who,' Stuart. What happens when she applies those skills to love, to adult things? Her abilities transcend 'Dr. Who.'"

Indeed, upstairs, in her bedroom, a few moments earlier, Allegra was working on a new song. It was not about "Dr. Who." It was reflective, and her first in a few weeks (three weeks was so long between songs that she'd just posted a video apology to fans for not posting more). She curled her legs beneath her and set her iMac in front of her. She bounced on the comforter and picked up her ukulele, strummed a few times, hummed a lilting melody, typed a little, then strummed some more, typed in more lines and sighed.

Then she sang:

"So my story of my life is a series of obsessions/ I go from/ one thing to ..."

She stopped, adjusted her fingers, strummed a lower note. "What rhymes with 'another'?" she asked, running a hand across the ukulele until lyrics coalesced in her head. Then she sang softly and with confidence: "My life is a series of obsessions/ I go from liking one thing to/ Liking another/ If you ask me a simple question/ I go on and on and on/ But it's not my fault there are so many things/ To love and admire/ So let me have my TV shows, let me have my movies/ Let me get obsessed/ Sometimes."

Her iPhone bleeped. She dropped her ukulele. "I bet that's Neil!" she said. Gaiman hadn't responded to her last tweet, the one asking for a comment. She grabbed for the phone and stared at the screen, then threw her head back and said: "It's not Neil. It's just my friend. She's crazy. She wrote, and I quote: 'Girl! Did Neil Gaiman just ask you out?'" An hour later, though, Gaiman did tweet back. He wrote to her, and I quote: "Tell them I think you're ridiculously talented, and can't wait to see what you do over the next decade."